If your Edgware roof already carries panels, on either side of the borough line, the question is no longer whether solar works there but whether to add a battery, so that more of what the panels make in daylight covers the evening instead of being exported. This guide covers what to check first, the two usual ways a battery joins an array, the paperwork with UK Power Networks and the published cost figures. If you are still deciding about the roof itself, start with our page on solar panels in Edgware.
Edgware is split between two boroughs, with a ward called Edgware in Barnet and another in Harrow, and the HA8 postcode district reaching into Brent. That matters for the counts below, which are borough-wide, but not for the battery itself: the same network operator and the same rules apply on both sides of the line.
How many Edgware-area roofs already have panels?
No one publishes a town-only figure. DESNZ records 3,477 solar PV installations of every size across Barnet at the end of 2025, with 15.95 MW of capacity, and 2,553 across Harrow, with 12.09 MW. Those counts include everything from a house roof to larger sites, and DESNZ says some 2025 installations could not yet be assigned to a local authority, so the figures are likely to rise when revised.
Harrow’s own records add a sharper local picture. Its Living Harrow climate strategy says that in the 2021 and 2022 Solar Together London rounds, more Harrow residents opted in than in any other London borough: 285 committed to panels and 139 of them also chose battery storage. That leaves 146 who committed to panels without a battery at the time (our arithmetic). If your Harrow-side Edgware home was one of them, this guide is about your next step.
Your existing array is the best evidence
Before anyone suggests a battery size, look at what your own panels do. The inverter display or app, and your export meter, show how much the array makes and how much leaves the house. For scale, PVGIS puts a 4 kWp, due-south roof in Edgware at about 3,938 kWh a year: about 474 kWh in June, roughly 15.8 kWh a day, and about 138 kWh in December, roughly 4.5 kWh a day (our arithmetic). A battery can only store what the house is not already using at the time. If your summer exports are small because someone is home all day, a battery adds less; if most of a June afternoon’s output leaves the house, there is something to capture. Our guide to what size home battery you need shows how to read your bills for the evening figure.
Two ways a battery joins an array
The first keeps your existing solar inverter and adds a battery with its own inverter, wired alongside. It leaves a working system alone and suits an Edgware house where the battery has to sit some way from the existing inverter, say in a side garage. The second replaces the old inverter with a hybrid inverter that runs both the panels and the battery. That can make sense where the original inverter is several years old, since inverters typically carry shorter warranties than panels. The survey decides which suits your wiring, your inverter and the space. In Edgware’s semis, 39.0% of households in Barnet’s Edgware ward and 48.3% in Harrow’s, a garage or utility room near the consumer unit is the usual first place to look, with siting set by the manufacturer’s manual and the PAS 63100 fire-safety standard.
The paperwork when a battery joins
Edgware town centre sits in UK Power Networks’ Eastern licence area on both sides of the borough boundary, and the battery is notified like the panels were. The installer counts your existing inverter and the new equipment together. Up to 16 A per phase, 3.68 kW, is a G98 notification, sent before commissioning or within 28 days after it; anything above needs a G99 application approved before work starts. UK Power Networks says it automatically approves applications where the maximum export, after any export limitation, is under 5 kW. If you are paid for exports, tell your supplier about the change; export rates are set by each supplier and must be above zero.
What it costs to add storage later
The Energy Saving Trust says a home battery can cost from £1,500 to £10,000, puts a 5 kWh system at around £4,600, says a typical home system might be 10 kWh and gives a typical lifespan of about 10 to 12 years. It also says fitting storage at the same time as panels costs less than a separate visit, which is the saving a retrofit gives up. DESNZ’s MCS battery statistics for 2025/26, covering existing homes only, show batteries of 1 to 5.99 kWh averaging 5.14 kWh at a mean of £1,280 per kWh, about £6,570 a job, and those of 6 to 10.99 kWh averaging 9.80 kWh at £870 per kWh, about £8,520 (our arithmetic). Larger batteries cost less per kWh but more in total. Battery installations carry 0% VAT until 31 March 2027, then 5%. How long the battery itself lasts is covered in our guide to how long solar batteries last.
One point on power cuts
A standard grid-tied battery shuts down when the grid does, so adding one to an Edgware array does not, by default, keep anything running in a power cut. Backup needs a backup-capable inverter or gateway and a dedicated circuit, designed in and priced separately.
Next step
Our battery storage in Edgware page covers the network side in more detail, and our solar panels in North London hub covers the wider area. Bring your inverter’s model and a year of generation or export readings to the survey if you have them. If a battery would not earn its place on your array, we will say so. You can ask for a survey through our contact page.
Sources: DESNZ, Renewable electricity by local authority 2014 to 2025, Solar PV sites and capacity, Barnet and Harrow (published 29 September 2026, end-of-2025 figures as first published); London Borough of Harrow, Living Harrow: Climate and Nature Strategy 2023–2030 (November 2023), section 2.1.3; ONS Census 2021, TS044, Edgware (Barnet) and Edgware (Harrow) wards, via Nomis; PVGIS 5.3, European Commission Joint Research Centre (PVGIS-SARAH3 2005–2023; 4 kWp, 35°, due south, 14% losses; Edgware run 15 October 2026); Energy Networks Association, EREC G98 Issue 2 (10 March 2025); UK Power Networks, licence boundaries open data and Solar and storage: cost, time and what’s involved; Energy Saving Trust, Battery storage (updated 19 August 2026); DESNZ, MCS-certified domestic battery installation statistics (28 May 2026); Ofgem, Smart Export Guarantee; HMRC, VAT Notice 708/6. Daily figures, differences and job averages are our arithmetic.